Responses of litter decomposition and nutrient release rate to water and nitrogen addition differed among three plant species dominated in a semi-arid grassland

Background and aims

Precipitation and nitrogen (N) deposition are predicted to increase in northern China. The present paper aimed to better understand how different dominant species in semi-arid grasslands in this region vary in their litter decomposition and nutrient release responses to increases in precipitation and N deposition.

Methods

Above-ground litter of three dominant species (two grasses, Agropyron cristatum and Stipa krylovii, and one forb, Artemisia frigida) was collected from areas without experimental treatments in a semi-arid grassland in Inner Mongolia. Litter decomposition was studied over three years to determine the effects of water and N addition on litter decomposition rate and nutrient dynamics.

Results

Litter mass loss and nutrient release were faster for the forb species than for the two grasses during decomposition. Both water and N addition increased litter mass loss of the grass A. cristatum, while the treatments showed no impacts on that of the forb A. frigida. Supplemental N had time-dependent, positive effects on litter mass loss of the grass S. krylovii. During the three-year decomposition study, the release of N from litter was inhibited by N addition for the three species, and it was promoted by water addition for the two grasses. Across all treatments, N and potassium (K) were released from the litter of all three species, whereas calcium (Ca) was accumulated. Phosphorus (P) and magnesium (Mg) were released from the forb litter but accumulated in the grass litter after three years of decomposition.

Conclusions

Our findings revealed that the litter decomposition response to water and N supplementation differed among dominant plant species in a semi-arid grassland, indicating that changes in dominant plant species induced by projected increases in precipitation and N deposition are likely to affect litter decomposition, nutrient cycling, and further biogeochemical cycles in this grassland. The asynchronous nutrient release of different species’ litter found in the present study highlights the complexity of nutrient replenishment from litter decomposition in the temperate steppe under scenarios of enhancing precipitation and N deposition.

     

Morphological and phylogenetic diversity of thermophilic cyanobacteria in Algerian hot springs

Geothermal springs in Algeria have been known since the Roman Empire. They mainly locate in Eastern Algeria and are inhabited by thermophilic organisms, which include cyanobacteria forming mats and concretions. In this work, we have investigated the cyanobacterial diversity of these springs. Cyanobacteria were collected from water, concretions and mats in nine hot springs with water temperatures ranging from 39 to 93 °C. Samples were collected for isolation in culture, microscopic morphological examination, and molecular diversity analysis based on 16S rRNA gene sequences. Nineteen different cyanobacterial morphotypes were identified, the most abundant of which were three species of Leptolyngbya, accompanied by members of the genera Gloeocapsa, Gloeocapsopsis, Stigonema, Fischerella, Synechocystis, Microcoleus, Cyanobacterium, Chroococcus and Geitlerinema. Molecular diversity analyses were in good general agreement with classical identification and allowed the detection of additional species in three springs with temperatures higher than 50 °C. They corresponded to a Synechococcus clade and to relatives of the intracellularly calcifying Candidatus Gloeomargarita lithophora. The hottest springs were dominated by members of Leptolyngbya, Synechococcus-like cyanobacteria and Gloeomargarita, whereas Oscillatoriales other than Leptolyngbya, Chroococcales and Stigonematales dominated lower temperature springs. The isolation of some of these strains sets the ground for future studies on the biology of thermophilic cyanobacteria.     

Deriving nutrient targets to prevent excessive cyanobacterial densities in U.S. lakes and reservoirs

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Response of dominant grassland species in the temperate steppe of Inner Mongolia to different land uses at leaf and ecosystem levels

In order to study the responses of dominant species to different land uses in the semiarid temperate grassland of Inner Mongolia, we tested the physiological responses of Stipa grandis, Leymus chinensis, and Artemisia frigida to mowing, grazing exclusion, and grazing land uses at the leaf and ecosystem levels. The grazing-exclusion and mowing sites released CO₂, but the grazing site was a net carbon sink. L. chinensis and S. grandis contributed more to the ecosystem CO₂ exchange than A. frigida. At the grazing-exclusion and mowing sites, Leymus chinensis and Stipa grandis both exhibited a higher light-saturation point and higher maximum photosynthetic rate than that at the grazing site, which increased photosynthesis and growth compared to those at the grazing site. In contrast, A. frigida possessed a higher nitrogen content than the other species, and more of the light energy used for photosynthesis, particularly at the grazing site.     

Centric diatoms from Lake Frolikha (Transbaikal area) and peculiarities of distribution of some taxa in Asia

The species composition of centric diatoms from Lake Frolikha (Transbaikal area) has been studied. The lake is located on the eastern shore of Lake Baikal and connected with it by a river. Twenty-three species of Centrophyceae from 7 genera (Aulacoseira, Cyclostephanos, Cyclotella, Discostella, Handmania, Pliocaenicus, and Stephanodiscus) have been found. The most represented genus is Aulacoseira (11 species). Fifteen species and 4 genera are new for the lake record. All revealed species are known in other lakes of the Baikal region; however Baikal endemics are absent in Lake Frolikha. The flora of centric diatoms in Lake Frolikha can be divided into two groups. The first group includes taxa common in Lake Baikal, and the second group includes taxa not typical for Lake Baikal. The level of differences between flora in Lake Baikal and Lake Frolikha is high (43%) despite the close location and connection to the river. An analysis of distribution of interesting species in Asia is presented.     

Effects of sediment-borne nutrient and litter quality on macrophyte decomposition and nutrient release

Macrophyte decomposition is a critical process that affects carbon and nutrient cycling, and energy flow, although the majority of the details involved in the process remain unclear. For the present study, a litter bag experiment was conducted to investigate the effects of sediment-borne nutrient and litter quality on the decomposition rates and nutrient release of four macrophyte life forms (emergent macrophyte: Phragmites australis, free-floating macrophyte: Hydrocharis dubia, floating-leaved macrophyte: Nymphoides peltata, submerged macrophyte: Ceratophyllum demersum), and a species mixture. Our results indicated that litter quality significantly influenced macrophyte decomposition and nutrient release. High-quality litter species (high initial nitrogen and phosphorus contents, as well as low C:N, C:P, and N:P ratios) decomposed more rapidly than low-quality litter species, and the initial C:N and C:P ratios, rather than the initial N and P contents, were effective indicators of the decomposition rate of macrophytes. Sediment-borne nutrients had little effect on the decomposition rate, yet a strong effect on the release of N and P, although the interactions between litter quality and sediment-borne nutrients significantly affected the decomposition rate. Three-way ANOVA analysis revealed that the litter quality imparted a more potent effect on the macrophyte decomposition rate and release of N and P than sediment-borne nutrients. These results implied that litter quality interacts with sediment-borne nutrients and may control macrophyte decomposition in shallow lakes.     

Allelopathic potential of Artemisia frigida and successional changes of plant communities in the northern China steppe

In the northern China steppe, overgrazing has decreased the abundance of many species that were originally dominant, but increased the abundance of Artemisia frigida. We aimed to determine whether the adaptive and competitive abilities of A. frigida are associated with allelopathy. Soil nutrient characteristics could not explain the poor growth of the originally dominant species. Volatile compounds released from A. frigida leaves and aqueous extracts (0.025, 0.05, 0.075, 0.10, and 0.15 g ml^?1) from A. frigida leaves and roots and from soil under A. frigida inhibited seed germination and seedling growth of three dominant species (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa). Allelopathic activity varied according to extract concentration, test species, and extract source. Germination was most strongly inhibited in S. krylovii, followed by L. chinensis and then C. squarrosa. Seedling growth was most strongly inhibited in L. chinensis, followed by S. krylovii and then C. squarrosa. Gas chromatography–mass spectrometry analyses of the leaf volatiles identified 27 compounds, primarily monoterpene or sesquiterpene compounds and their oxygen-containing derivatives, such as eucalyptol, beta.-myrcene, 1,6-octadien-3-ol,3,7-dimethyl, 3-carene, bicyclo[2.2.1]heptan-2-one,1,7,7-trimethyl-,(1R), cis-sabinenehydrate, camphene, and alpha-Pinene. These findings suggest that allelochemicals from A. frigida can modify the surrounding micro-habitat. The responses of target plants to allelopathy of A. frigida may be one reason for changes in plant community succession in the northern China steppe.     

Species of Nectria (Ascomycetes,Hypocreales) having orange perithecia and colorless,striate ascospores

Nine species ofNectria are described or redescribed. Ascospores of all are colorless and striates; their perithecia are orange and do not become red in KOH. Three groups of species are represented. One group includesNectria grammicospora, N. cf.grammicospora, N. subquaternata, and the new species:N. grammicosporopsis, N. lucifer, andN. neogrammicospora. A second group includes the new speciesN. chlorogloea andN. septomyrotheciae. The third group is represented by the single new speciesN. dacryocarpa. The life-cycles of these species are described. Anamorphs ofN. grammicospora, N. grammicosporopsis, N. lucifer, andN. subquaternata are species ofClonostachys. The anamorph, ofN. neogrammicospora isAcremonium- orCephalosporiopsis-like in having monophialidic conidiophores and phragmosporous conidia, and that ofN. cf.grammicospora isAcremonium-like with amerosporous conidia. The anamorphs ofN. chlorogloea andN. septomyrotheciae have green conidia. The anamorph ofN. chlorogloea isMyrothecium sp.; its conidia are unicellular and the conidioma is a synemma. The anamorph ofN. septomyrotheciae isSeptomyrothecium cf.uniseptatum; its conidioma is a sporodochium and the conidia are bicellular. The new genus and speciesDacryoma alba are described for the anamorph ofN. dacryocarpa. All of these fungi are pantropical or Australasian in distribution.     

<Emphasis Type="Italic">Artemisia frigida</Emphasis> and <Emphasis Type="Italic">Stipa krylovii</Emphasis>, two dominant species in Inner Mongolia steppe,differed in their responses to elevated atmospheric CO<Subscript>2</Subscript> concentration

Aims

Despite extensive studies on effects of elevated CO₂ concentration ([CO₂]_e) on plant growth, few studies have investigated the responses of native grassland plant species to [CO₂]_e in terms of nutrient acquisition.

Methods

The effects of [CO₂]_e (769 ± 23 ppm) on Artemisia frigida and Stipa krylovii, two dominant species in Inner Mongolia steppe were investigated by growing them for 7 weeks in Open-Top Chambers (OTC).

Results

Exposure to [CO₂]_e enhanced shoot and root growth of A. frigida and S. krylovii. Elevated [CO₂] increased photosynthetic rates (Pn) by 34 % in A. frigida but decreased Pn by 52 % in S. krylovii. Moreover, root-secreted acid phosphatase activity in A. frigida was stimulated by [CO₂]_e, while exudation of malate from roots of S. krylovii was suppressed by [CO₂]_e. Exposure to [CO₂]_e led to a decrease in P concentration in shoots and roots of A. frigida and S. krylovii, but total amount of P accumulated in shoots and roots of both species was increased by [CO₂]_e.

Conclusions

The two dominant species in temperate steppes differed in their responses to [CO₂]_e, such that A. frigida was more adapted to [CO₂]_e than S. krylovii under low availability of soil P.

     

Nitrogen, phosphorus and potassium nutritional status of semiarid steppe grassland in Inner Mongolia

In grazed semiarid steppe ecosystems, much attention has been paid to aspects of growth limitation by water. So far, potential limitation of primary production by plant nutrients was rarely considered. This knowledge is essential for identification of sustainable land-use practices in these large and important ecosystems on the background of over-exploitation and climate change. In the present study plant nutrient concentrations and ratios were investigated with factorial additions of water and N fertilizer at two sites with contrasting soil nutrient availability. Combined analysis of nutrient concentrations, contents, biomass production, and plant N:P ratios consistently confirmed primary growth limitation by water and a strong N limitation when sufficient amounts of water were supplied. P limitation only occurred at the site with low P availability when in addition to the natural supply, water and N fertilizer were given. According to reported thresholds of N:K and K:P ratios, K was not limiting in any plot. The observed nutritional patterns in the plant community were related to the dynamics of species composition and their specific nutrient status. Stipa grandis had the highest N:P ratio whereas Artemisia frigida showed lowest N:P. These nutrient characteristics were related to growth strategies of dominant species. Accordingly, the relative biomass contribution of S. grandis and A. frigida strongly affected the nutrient status of the plant community. Plant N:P ratios indicate the relative limitation by N or P in the semiarid grasslands under sufficient water supply, but other methods of nutritional diagnosis should be used when plant N:P ratios remain below critical values.     

Early responses of drought-resistant and -susceptible tomato plants subjected to water stress

Three-week-old seedlings of one drought-susceptible tomato cultivar (Lycopersicon esculentum cv. “New Yorker”) and two drought-resistant species of tomato (Solanum pennellii andLycopersicon chilense) were subjected to various degrees of PEG 8000-induced water stress from ?0.017 to ?1.0 MPa for a duration of 24 h so that their early responses to water stress could be compared. Such a comparison would determine if there was a relationship to root cytokinin levels following sudden induction of water stress in the drought-resistant species. Transpiration rates of leaves were monitored throughout the 24-h period, shoots were evaluated for leaf water potential (LWP), and roots were extracted for levels oft-zeatin riboside (t-ZR) and dihydrozeatin riboside (DHZR) using a monoclonal antibody enzyme immunoassay. Transpiration rates were evaluated gravimetrically by difference every 6 h up to 24 h. Transpiration rate decreased with increasing PEG levels and passage of time in all three species, measured at 6 and 12 h, logarithmically in the case of the twoLycopersicon species and linearly in the case ofSolanum. From 12–18 h (while plants were in darkness), transpiration rate was a function of the level of PEG only and not time in all three species. When light resumed from 18–24 h, only 5.pennellii showed no further decrease in transpiration rate over time with increasing PEG. Drought-susceptibleL. esculentum had a stronger linear decrease in LWP with increasing PEG 8000 concentration than the other two species.L. esculentum also had a higher initial transpiration rate than did either of the drought-resistant species. The two drought-resistant species showed less change in LWP with 5.pennellii having a small decrease andL. chilense having little change. OnlyS. pennellii exhibited a decrease in roott-ZR levels, which may imply a role for root cytokinin within the first 24-h exposure to water stress in this species.L. esculentum exhibited no change in roott-ZR. The levels oft-ZR inL. chilense were less than that ofL. esculentum but showed only a slight decrease with increasing PEG.S. pennellii andL. chilense, although both drought-resistant tomato species, showed different patterns of response with respect to pattern of decline in transpiration rate, LWP, and roott-ZR levels.     

Trophic Segregation of Small Carnivorans (Carnivora: Mustelidae and Mephitidae) from the Southern Cone of South America

Remarkable adaptations in the Carnivora have evolved as a way of dealing with feeding competition, accentuating hypocarnivorous or hypercarnivorous morphotypes. The Carnivora is a highly successful order with 47 living species in South America. Their history in South America is recent, and includes few lineages that arrived before the Panamanian bridge was completed (procyonids), and others that arrived later (felids, mephitids). Here, we evaluated the trophic segregation of small carnivorans (Conepatus chinga, Galictus cuja, Lontra provocax, Lyncodon patagonicus, and the introduced Neovison vison) from southern South America, using a geometric morphometric approach, i.e., Principal Component and Canonical Variate Analysis, to study shape variations and t-tests to study size variation. We also performed Canonical Phylogenetic Ordination to study the association between shape, size, diet, and phylogeny. We identified C. chinga as the most hypocarnivorous member of the guild, G. cuja, L. patagonicus, and N. vison as hypercarnivores, with L. provocax in an intermediate position. Semiaquatic habits segregate Lontra provocax, and partially N. vison, from other species. Significant differences in size were observed between all species pairs, except C. chinga and N. vison. Phylogeny accounts for a very important part of morphological variance, with cladogenetic events between mustelids and mephitids responsible for almost 55 % of it. The small carnivoran guild of southern South America is represented by species adapted to different feeding strategies, with C. chinga and L. provocax preying mainly on invertebrates, G. cuja and L. patagonicus specifically on small vertebrates, and the non-native N. vison with a highly diverse diet.     

Long-Term Nitrogen Addition Leads to Loss of Species Richness Due to Litter Accumulation and Soil Acidification in a Temperate Steppe

Background

Although community structure and species richness are known to respond to nitrogen fertilization dramatically, little is known about the mechanisms underlying specific species replacement and richness loss. In an experiment in semiarid temperate steppe of China, manipulative N addition with five treatments was conducted to evaluate the effect of N addition on the community structure and species richness.

Methodology/Principal Findings

Species richness and biomass of community in each plot were investigated in a randomly selected quadrat. Root element, available and total phosphorus (AP, TP) in rhizospheric soil, and soil moisture, pH, AP, TP and inorganic N in the soil were measured. The relationship between species richness and the measured factors was analyzed using bivariate correlations and stepwise multiple linear regressions. The two dominant species, a shrub Artemisia frigida and a grass Stipa krylovii, responded differently to N addition such that the former was gradually replaced by the latter. S. krylovii and A. frigida had highly-branched fibrous and un-branched tap root systems, respectively. S. krylovii had higher height than A. frigida in both control and N added plots. These differences may contribute to the observed species replacement. In addition, the analysis on root element and AP contents in rhizospheric soil suggests that different calcium acquisition strategies, and phosphorus and sodium responses of the two species may account for the replacement. Species richness was significantly reduced along the five N addition levels. Our results revealed a significant relationship between species richness and soil pH, litter amount, soil moisture, AP concentration and inorganic N concentration.

Conclusions/Significance

Our results indicate that litter accumulation and soil acidification accounted for 52.3% and 43.3% of the variation in species richness, respectively. These findings would advance our knowledge on the changes in species richness in semiarid temperate steppe of northern China under N deposition scenario.     

Freshwater Crustacea (Cladocera,Copepoda) of Iceland: taxonomy,ecology, and biogeography

Of the many types of freshwater bodies across Iceland (e.g., lakes, springs, rivers, and ponds), greater effort has been invested in researching the freshwater Crustacea (Cladocera, Copepoda) of more permanent, larger, and deeper water bodies than on smaller or more ephemeral sites. To address this, we described the fauna of 12 shallow freshwater bodies distributed from the coast to the central highlands of Iceland. We identified 16 species in 11 genera belonging to six families of Cladocera, and 12 species in eight genera belonging to four families of Copepoda. Five of the species we identified (Alona werestschagini, Cyclops vicinus, Daphnia cristata, Diacyclops abyssicola, and Heterocope borealis) represent new distribution records for Iceland, increasing the number of species now known from this region to 34 Cladocera and 38 Copepoda taxa. Additionally, we discuss the taxonomy of some species with doubtful taxonomical status. Six crustacean taxocenes are described, each characterized by the dominance of different taxa, with bottom sediment characteristics best explaining species assemblage structure. We evaluated the relationships between Icelandic Cladocera and Copepoda faunas and those of the adjacent Svalbard, Faroe, and Shetland Islands, Greenland, and the mainland Norway. The taxonomic composition of the Icelandic fauna is dominated by widely distributed Holarctic, and secondarily Palaearctic and Nearctic species, and is more similar to the faunas of the major North Atlantic islands (64.2–71.8 % similarity) than it is to that of continental Norway.     

The diversity of endophytic fungi in the above-ground tissue of two Lycopodium species in Poland

Endophytes are a large and diverse group of fungi that colonize healthy plant tissues without causing any symptoms. The majority of studies have focused on angiosperm and conifer hosts and few have examined the endophytes of lycophytes. In the present study, we characterized culturable endophytic fungi in two closely related Lycopodium species (L. annotinum and L. clavatum) from pine, beech, oak and spruce forests across Poland. More than 400 strains were isolated but only 18 Ascomycete species were identified. Members of the Dothideomycetes dominated the fungal endophyte communities in Lycopodium. The most abundant taxa cultured were Phoma brasiliensis (from L. clavatum) and Paraconiothyrium lycopodinum (from L. annotinum). Five taxa were isolated exclusively from L. annotinum, but only two of them (Paraconiothyrium lycopodinum and Mycosphaerella sp.) were relatively abundant. Two taxa were only found in L. clavatum, namely: Stagonospora pseudovitensis and an unidentified Dothideomycete. The taxon assigned as Ascomycota 2 (SH219457.06FU) was isolated only from strobili of both host species. Direct PCR and cloning from L. annotinum shoots revealed a substantially greater endophyte richness compared with the results from culturing.     

Resistance to desiccation in aquatic invasive snails and implications for their overland dispersal

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Plant and animal communities in brackish supra-littoral pools (‘dobben’) in the northern part of the Netherlands

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Nitrogen Forms Influence Microcystin Concentration and Composition via Changes in Cyanobacterial Community Structure

The eutrophication of freshwaters is a global health concern as lakes with excess nutrients are often subject to toxic cyanobacterial blooms. Although phosphorus is considered the main element regulating cyanobacterial biomass, nitrogen (N) concentration and more specifically the availability of different N forms may influence the overall toxicity of blooms. In this study of three eutrophic lakes prone to cyanobacterial blooms, we examined the effects of nitrogen species and concentrations and other environmental factors in influencing cyanobacterial community structure, microcystin (MC) concentrations and MC congener composition. The identification of specific MC congeners was of particular interest as they vary widely in toxicity. Different nitrogen forms appeared to influence cyanobacterial community structure leading to corresponding effects on MC concentrations and composition. Total MC concentrations across the lakes were largely explained by a combination of abiotic factors: dissolved organic nitrogen, water temperature and ammonium, but Microcystis spp. biomass was overall the best predictor of MC concentrations. Environmental factors did not appear to affect MC congener composition directly but there were significant associations between specific MC congeners and particular species. Based on redundancy analyses (RDA), the relative biomass of Microcystis aeruginosa was associated with MC-RR, M. wesenbergii with MC-LA and Aphanizomenon flos-aquae with MC-YR. The latter two species are not generally considered capable of MC production. Total nitrogen, water temperature, ammonium and dissolved organic nitrogen influenced the cyanobacterial community structure, which in turn resulted in differences in the dominant MC congener and the overall toxicity.     

The distribution of species of the genusThermocyclops (Copepoda,Cyclopoida) in the western hemisphere,with description ofT. parvus,new species

The distribution and ecology of species of cyclopoid copepods of the genusThermocyclops in the western hemisphere are reviewed. These are:Thermocyclops brehmi (Kiefer),T. crassus (Fischer),T. decipiens (Kiefer),T. hastatus antillensis Herbst,T. inversus (Kiefer),T. minutus (Lowndes),T. tenuis (Marsh),T. tenuis longifurcatus Pesce, andT. parvus, new species.T. brehmi is known from microlimnotopes in a restricted region in northern Argentina and Uruguay, whileT. crassus has been reliably recorded only from small ponds in Costa Rica.T. decipiens, with many records from northern Argentina to Costa Rica, Guatemala and the Antilles, is often numerous in mesotrophic and eutrophic lakes and reservoirs. The range ofT. minutus extends over tropical and subtropical lowlands of South America from northern Argentina to Venezuela; this species prefers oligotrophic and mesotrophic conditions in larger lakes.T. inversus may prefer mildly carbonate waters and inhabits large and small reservoirs, natural lakes, ponds, wells and caves from northeastern Brazil to Mexico and the Antilles.T. tenuis ranges from northern Argentina to the Antilles and the southern United States, inhabiting large and small, natural and artificial bodies of water.T. tenuis longifurcatus is known only from two wells on Bonaire,T. hastatus antillensis from a well on the island of Guadeloupe, andT. parvus only from plankton samples from the Florida Everglades. Knowledge of population dynamics, feeding and reproductive biology of several planktonic species is reviewed.     

Adaptations in phytoplankton life strategies to imposed change in a shallow urban tropical eutrophic reservoir,Garças Reservoir,over 8 years

This study aimed at evaluating the phytoplankton adaptive strategies of phytoplankton in a shallow urban eutrophic tropical reservoir, Garças Reservoir, over temporal and vertical scales. Samples were taken monthly for eight consecutive years (1997–2004) at a fixed set of depths in the water column. At the beginning, the reservoir was eutrophic with 20% of its surface covered by water hyacinth Eichhornia crassipes (phase I). Then, in phase II, water hyacinth grew to cover up to 40–70% of the surface. In phase III it was mechanically removed. After macrophyte removal the limnology changed, drastically. This removal modified nutrient dynamics, drastically reduced water transparency, and increased both primary production and phytoplankton biomass, the latter impeding light penetration. Phytoplankton life strategies during water hyacinth dominance (phase II) responded promptly to this environmental disturbance in conditions of low dissolved oxygen (DO) and soluble reactive phosphorus (SRP) and high free CO₂ values. After macrophyte removal, a permanent cyanobacterial monoculture was established. Phase I was dominated basically by Sphaerocavum brasiliense, mainly during the stratified months, represented by non-flagellate colonies, the M functional group, S-strategists, and greater biomass of species with high maximal axial linear dimension (MLD) and cell volumes. Phase II was dominated by Cryptomonas curvata, C. erosa, C. marssonii, Trachelomonas sculpta, T. volvocinopsis, T. kelloggii, T. hispida, Peridinium spp., Aphanocapsa spp., and Aphanothece spp., and was represented by unicellular flagellate species, Y, W2, K, L_O functional groups, and C-strategists, greater biomass of species with intermediate MLD and cell volumes. Phase III was dominated by Microcystis aeruginosa, M. panniformis, Cylindrospermopsis raciborskii, Planktothrix agardhii, and Aphanizomenon gracile, represented by non-flagellate colonies, M, S, H1, S functional groups, and S and R-strategists, greater biomass of species with high MLD and cell volumes (>50 μm and >10⁴ μm³, respectively).